Answer:
A. the charge on their ions
Explanation:
Elements are grouped into the same group in the periodic table if they have the same valence electrons. However, the number of valence electrons an element has, determines the number of charges it can possess.
According to this question, two elements in the same group of the periodic table will have the same charge on their ions because they both have the same number of valence electrons.
Find the energy of a photon with a wavelength of 820. nm?
Answer: The energy of a photon with a wavelength of 820 nm is [tex]2.42 \times 10^{-19} m[/tex].
Explanation:
Given : Wavelength = 820 nm
Convert nm into meter as follows.
[tex]1 nm = 10^{-9}\\So, 820 nm = 820 nm \times \frac{10^{-9} nm}{1 nm}\\= 820 \times 10^{-9} m[/tex]
The relation between energy and wavelength is as follows.
[tex]E = \frac{hc}{\lambda}[/tex]
where,
E = energy
h = Planck's constant = [tex]6.63 \times 10^{-34} kg m^{2}/s[/tex]
c = speed of light = [tex]3.0 \times 10^{8} m/s[/tex]
[tex]\lambda[/tex] = wavelength
Substitute the values into above formula as follows.
[tex]E = \frac{hc}{\lambda}\\= \frac{6.63 \times 10^{-34} kg m^{2}/s \times 3.0 \times 10^{8} m/s}{820 \times 10^{-9} m}\\= \frac{1.989 \times 10^{-25}}{820 \times 10^{-9}}\\= 2.42 \times 10^{-19} m[/tex]
Thus, we can conclude that energy of a photon with a wavelength of 820 nm is [tex]2.42 \times 10^{-19} m[/tex].
What type of ions are commonly formed from halogens
Answer:
they all form diatomic molecules.
for example: H2, F2, Cl2, Br2, I2, and At2) and they all form negatively charged ions H-, F-, Cl-, Br-, I-, and At- .
can someone do this for me i wasent there when we learned it
If 1.00 L of gas at 1.00 atm of pressure is compressed to a volume of 0.473 L, what is the new pressure of the gas?
Answer:
2.11
Explanation:
1/0.473 = 2.11
Pb(NO3)2 (aq) + 2 NaI (aq) --> PbI2 (s) + 2 NaNO3 (aq)
Starting with with 50.0 grams of Pb(NO3)2 and 30.0 grams of NaI:
A. What is the limiting reagent?
B. How many grams of the excess reactant remains?
C. How many grams of each product is formed?
D. If 12 grams of NaNO3 actually formed in the reaction, what is the percent yield of this reaction?
Answer:
Explanation:
Moles of Pb(NO3)2 = mass/molecular mass
= 50.0 grams/(207.20*1 + 14.01*2 + 16*6)
= 50.0 grams/331.22
= 0.15 moles
Moles of NaI
= 30/(22.99+126.9)
= 30/149.89
= 0.2 Moles
A. NaI is less 2x Pb(NO3)2 so NaI is the limiting reagent.
B. The ratio is 1 to 2 so there is 0.15 - 0.2/2 = 0.05 mole
or 16.78 grams of Pb(NO3)2 left.
C. As NaI is limiting, only 0.2 Moles of NaNO3 is formed.
Mass = Moles * Molecular Mass
Molecular Mass of NaNO3 can be calculated as:
Na - 22.99
N - 14.01
O - 3(16) = 48
23+14+48 = 85gram / mole
Thus, Mass = 0.2*85 = 17 gram of NaNO3
Mass is conserved in a chemical reaction.
Mass of PbI2 can be calculated as:
50+30-16.78-17
= 46.3 gram of PbI2
Mass =
12.75
Thus, 12.75g of Sodium Nitrate can be formed
Answer:
Explanation:
Pb(NO3)2 (aq) + 2 NaI (aq) --> PbI2 (s) + 2 NaNO3 (aq)
MM for each compound -
Pb(NO3): 207 + 14x2 + 16x3x2 = 331
PI2: 207 + 127x2 = 461
NaI: 23 + 127 = 150
NaNO3: 23 + 14 + 16x3 = 85
Moles of Pb(NO3)2 = 50/331 = 0.15
Moles of NaI = 30/150 = 0.2
Ratio of moles is 1:2
So NaI is limiting
Limited to 0.2/2 = 0.1 mole of Pb(NO3)2
Excess = 0.15 - 0.1 = 0.05 mole
Mass remains = 0.05x331 = 16.55 grams
Moles of NaNO3 formed = Moles of NaI reacted = 0.2
Mass = 0.2x85 = 17 grams
Moles of PbI2 formed = Moles of Pb(NO3)2 reacted = 0.1
Mass = 0.1x461 = 46.1 grams
If 12 grams of NaNO3 actually formed in the reaction,
percent yield = 12/17x100% = 70.6%
What happens to the end of the O2 molecule that is closest to the positive end of the H2O molecule?
Hydrogen bond will be formed when the end of the O₂ molecule that is
closest to the positive end of the H₂O molecule.
What is Hydrogen bond?These are referred to as electrostatic force which occurs between
Hydrogen atom and other electronegative atom bearing a lone pair of
electrons.
Oxygen is electronegative and has lone pair of electrons which is why the
bond formed will be Hydrogen bond.
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Calculate the amount of heat energy required to heat up 15.9 grams of ice from -4 °C to 14°C.
Answer:
581 Joules.
Explanation:
Using the formula;
Q = m × c × ∆T
Where;
Q = amount of heat absorbed (J)
m = mass of substance (g)
c = specific heat capacity (J/g°C)
∆T = change in temperature (°C)
According to the information provided in this question;
Q = ?
mass of ice = 15.9g
initial temperature = -4°C
final temperature = 14°C
Hence, ∆T = 14 - (-4) = 14 + 4 = 18°C
specific heat capacity (c) of ice in J/g°C = 2.03 J/g°C
Using Q = m × c × ∆T
Q = 15.9 × 2.03 × 18
Q = 32 × 18
Q = 581 Joules.
In the decomposition of KCLO3, how many moles of KCL are formed in the reaction that produces 0.05 moles of O2?
Answer:
0.033 moles of KCl are formed.
Explanation:
The reaction that takes place is:
2KClO₃ → 2KCl + 3O₂To solve this problem we need to convert 0.05 moles of O₂ into moles of KCl, to do so we use the stoichiometric coefficients of the balanced reaction:
0.05 mol O₂ * [tex]\frac{2molKCl}{3molO_2}[/tex] = 0.033 mol KClIf 0.05 moles of O₂ are produced, then 0.033 moles of KCl are formed as well.
Summary of exothermic and endothermic
Please help with the chart 10 questions
1. Which type of energy is representing by the moving of objects?
2. What type of energy is stored?
3. Explain the lot of conversation of energy?
4. A metal spoon and a wooden spoon are placed in a pot of boiling water. What property of the metal spoon causes it to become hotter than the wooden spoon and why?
5. The thing we measure when we want to determine the average kinetic energy of random motion is the particles of a substance is ___________.
6. The __________ is the energy needed to raise the temperature of a substance by 1°C.
7. A(n) ________ reaction is one where the products have lower energy than the reactants.
8. __________ reaction requires energy in order to take place.
9. The __________ is used to describe how much energy is produced or used during a chemical change.
Types of chemical bonds & names
Answer:
There are three primary types of bonding: ionic, covalent, and metallic. Definition: An ionic bond is formed when valence electrons are transferred from one atom to the other to complete the outer electron shell.
Explanation:
What is the name of the element represented in the model?
O A. Beryllium
B. Boron
O C. Oxygen
O D. Flourine
Answer:
Your answer is B
Boron
Good luck
Explanation:
How many moles of propane gas would be present in 11 grams
of the gas at standard conditions?
Mole measure the number of elementary entities of a given substance that are present in a given sample. Therefore, 0.24moles of propane gas would be present in 11 grams of the gas at standard conditions.
What is mole?The SI unit of amount of substance in chemistry is mole. The mole is used to measure the quantity or amount of substance. We know one mole of any element contains 6.022×10²³ atoms which is also called Avogadro number.
Mathematically,
mole of substance =given mass of substance ÷ molar mass of substance
Molar mass of 1 mole of propane gas= 44.0956 g/mol
Given mass of propane gas=11 grams
Substituting all the given values in the above equation, we get
mole of substance =11 grams ÷44.0956 g/mol
mole of substance =0.24moles
Therefore, 0.24moles of propane gas would be present in 11 grams
of the gas at standard conditions.
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What is the pOH of a solution that has an H+=7.7x10^-7 M
Answer:
Explanation:
Step 1
The question is based on the concept of PH and pOH calculations.
pH is defined as negative logarithmic of hydronium Ion concentration.
while pOH is defined as negative logarithmic of hydroxide ion concentration of the solution.
Step 2
[H+] = 7.7*10-7 M
pH = -log[H+]
= -log ( 7.7*10-7 )
= 6.12
Step 3
pOH = 14 - pH
= 14 - 6.11
= 7.89
P waves are classified as
O Surface Waves
Or
O. Body waves
Help plzzzz
Answer:
Surface
Explanation:
If Earth is in between the sun and the Moon in both Image 1 and Image 2, why do you think a lunar eclipse is only happening in Image 2?
Answer: well I don’t have either picture but here goes anyway. It could be that the suns rotation matched up with the moon being 400 miles away from it and 400 times bigger it could be in image 1 the sun is only at a partial eclipse. With no images kinda had to wing it but I hope it helps :D
A lunar eclipse is an event that occurs when the sun, moon, and earth are aligned. It is happening in image 2 as Earth is obstructing the sun’s light.
What is a lunar eclipse?In lunar eclipse Earth completely covers the surface of the moon which makes the surface look red and dark. It happens only when the Moon is opposite the sun in the sky.
It is not seen in the first image as the earth is incapable of totally blocking the sunlight and hence does not result in a lunar eclipse. In the second image, the Earth has covered the whole surface of the moon and hence is blocking the sunlight.
Therefore, a lunar eclipse is seen only in image 2.
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Science help due by 11:59 What is gravity like on other planets
compared to Earth?
Explanation:
Mercury 0.377 g
Venus 0.905 g
Earth 1 g (midlatitudes)
Moon 0 .165 7 g (average)
The amount of energy transferred per unit time by an electrical appliance is measured in what? Give the
name not the symbol.
Answer:
The Watt
Explanation:
Electric power is the rate, per unit time, at which electrical energy is transferred by an electric circuit. The SI unit of power is the watt, one joule per second.
The amount of energy transferred per unit time is called power, and power is measured in Watt.
What is Watt?Watt is the unit of power. It is used to measure the transfer of power. This is named after James Watt.
When one joule of energy is transferred in one second, this is the power of the Watt.
Thus, the amount of energy transferred per unit time is called power, and power is measured in Watt.
Learn more about Watt
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How do you determine a limiting or excess reagent?
give me some sort of equation to follow, no links please
Answer:
The reactant that produces a lesser amount of product is the limiting reagent. The reactant that produces a larger amount of product is the excess reagent. To find the amount of remaining excess reactant, subtract the mass of excess reagent consumed from the total mass of excess reagent given.
plzz mark me as brainliest
The air in a living room has a mass of 60 Kg and a specific heat of 1,020 J/kg°C. What is the change in thermal energy of the air when it warms from 20°C to 25°C?
Answer:
Q = 306 kJ
Explanation:
Given that,
Mass, m = 60 kg
Specific heat, c = 1020 J/kg°C
The temperature changes from 20°C to 25°C.
Let Q be the change in thermal energy. The formula for the heat released is given by :
[tex]Q=mc\Delta T[/tex]
Put all the values,
[tex]Q=60\times 1020\times (25-20)\\\\Q=306000\ J\\\\or\\\\Q=306\ kJ[/tex]
So, 306 kJ is the change in thermal energy.
P4 +6Br2 --> 4PBr3
What is the ratio of the moles of P4 consumed to moles of PBr3 produced?
Answer:
1 mole of P₄ consumed:4 moles of PBr₃ produced
Explanation:
Look at the coefficients in the balanced chemical equation to determine the ratios. For every 1 mole of P₄ consumed (P₄ has a coefficient of 1), 4 moles of PBr₃ would be produced (PBr₃ has a coefficient of 4).
Answer:
[tex]\boxed {\boxed {\sf 1 \ mole \ P_4 consumed \ to \ 4 \ moles \ PBr_3 \ produced}}[/tex]
Explanation:
To find the mole ratio, we must use the coefficients.
[tex]P_4+6Br_2 \rightarrow 4PBr_3[/tex]
This equation is balanced (4 atoms of P and 12 atoms of Br on both sides), so we can go straight to the coefficients.
P₄ doesn't have a coefficient, so 1 is implied Br₂ has a coefficient of 6PBr₃ has a coefficient of 4So according to the coefficients above, for every 1 mole of P₄ that is consumed, 4 moles of PBr₃ are produced. Therefore, the ratio is 1 mole P₄ to 4 moles of PBr₃.
Which subatomic particle orbits the nucleus?
O the electron
o the neutron
O the proton
it’s electron btw
Answer: Subatomic particle which orbits the nucleus is electron.
Explanation:
Every atom contains three sub-atomic particles. These are protons, neutrons and electrons.
Protons contain a positive charge, neutrons have no charge and electrons have a negative charge.
Both protons and neutrons reside inside the nucleus of the atom whereas electrons reside outside the nucleus of atom and revolve around the nucleus.
Therefore, it is concluded that subatomic particle which orbits the nucleus is electron.
If you want to make 174 grams of NiFz, how many moles of HF will you need, using
the following balanced chemical equation? Ni + 2 HF - NiF2 + H2
Answer:
3.6mol
Explanation:
The balanced chemical equation of this reaction is given as follows:
Ni + 2HF → NiF2 + H2
Based on the above equation, 2 moles of HF will react to produce 1 mole of NiF2.
According to this question, to make 174 grams of NiF2, we find the number of moles of HF required. However, we first convert the mass value of NiF2 to mole value using;
mole = mass/molar mass
Molar mass of NiF2 = 58.7 + 19(2)
= 58.7 + 38
= 96.7g/mol
mole = 174/96.7
mole = 1.799mol of NiF2
Hence, if 2 moles of HF will react to produce 1 mole of NiF2.
- 1.799mol of NiF2 will require (1.799 × 2) = 3.598
= 3.6mol of HF.
write 2 typical properties that are only common to transition metals
Answer:
Properties of transition elements
they are all metals and that most of them are hard, strong, and lustrous, have high melting and boiling points, and are good conductors of heat and electricity.
How is matter conserved through cellular respiration
Answer:
In cellular respiration, complex molecules containing carbon react with oxygen to produce carbon dioxide and other materials. ... Matter is conserved during cellular respiration because atoms are conserved in physical and chemical processes
Explanation:
I hope this helps
4. What coefficients do you need to balance the following equation?
CH4 + O2 + CO2 + H2O
O 1, 2, 1, 2
O 2, 1, 1, 1
O 1, 1, 1, 1
O 2, 1, 2, 2
Answer:
option first is the right answer
How many atoms are in 25.00 g of B.
1.393 x 10^24 atoms of B
1.333 x 10^23 atoms of B
2.16 x 10^26 atoms of B
2.17 x 10^24 atoms of B
Answer:
[tex]\boxed {\boxed {\sf 1.393 *10^{24} \ atoms \ B}}[/tex]
Explanation:
1. Convert Grams to Moles
Use the molar mass (found on the Periodic Table) to convert from grams to moles.
Boron (B): 10.81 g/molUse this value as a ratio.
[tex]\frac {10.81 \ g \ B }{1 \ mol \ B}[/tex]
Multiply by the given number of grams.
[tex]25.00 \ g \ B *\frac {10.81 \ g \ B }{1 \ mol \ B}[/tex]
Flip the ratio so the grams of boron cancel out.
[tex]25.00 \ g \ B *\frac {1 \ mol \ B }{10.81 \ g \ B}[/tex]
[tex]25.00 *\frac {1 \ mol \ B }{10.81 }[/tex]
[tex]\frac {25.00 \ mol \ B }{10.81 }=2.312673451 \ mol \ B[/tex]
2. Convert Moles to Atoms
We use Avogadro's Number, 6.02*10²³: the number of particles (atoms, molecules, etc.) in 1 mole of a substance. In this case, the particles are atoms of boron.
[tex]\frac {6.02*10^{23} \ atoms \ B} {1 \ mol \ B}[/tex]
Multiply by the number of moles we calculated.
[tex]2.312673451 \ mol \ B *\frac {6.02*10^{23} \ atoms \ B} {1 \ mol \ B}[/tex]
The moles of boron cancel.
[tex]2.312673451 *\frac {6.02*10^{23} \ atoms \ B} {1 }[/tex]
[tex]2.312673451 *6.02*10^{23} \ atoms \ B} =1.39269195*10^{24} \ atoms \ B[/tex]
The original value of grams has 4 significant figures, so our answer should have the same. For the number we calculated, that is the thousandth place.
[tex]1.392\underline69195*10^{24} \ atoms \ B[/tex]
The 6 tells us to round the 2 to a 3.
[tex]1.393 *10^{24} \ atoms \ B[/tex]
25.00 grams of boron is equal to 1.393*10²⁴ atoms.
A ball is sitting at the top of a ramp. As the ball rolls down the ramp, the potential energy of the ball decreases. What happens to the potential energy as the ball moves
Answer:
it is converted to kinetic energy
Which element, when combined with phosphorus, would form an ionic compound?
A) Carbon.
B)Oxygen.
C)Magnesium.
D)Boron.
There are two types of chemical compound one is covalent compound and other is ionic compound, covalent compound formed by sharing of electron and ionic compound formed by complete transfer of electron. Therefore, the correct option is option C.
What is chemical Compound?Chemical Compound is a combination of molecule, Molecule forms by combination of element and element forms by combination of atoms in fixed proportion.
An ionic compound is a metal and nonmetal combined compound. Ionic compound are very hard. They have high melting and boiling point because of strong ion bond.
Since phosphorus is a nonmetal, we need a metal. Out of given option the only element that is metal is Magnesium while others are non metal.
Therefore, the correct option is option C.
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Which of the gas laws takes into account the forces of attraction between molecules based on the characteristics of the gas? *
Ideal Gas Law
Boyle's Law
Charles's Law
Van der Waals's Law
In the reaction shown above , the?
Answer:
I think option (d) is right answer
